Energy recover ventilator units recover energy from exhaust air for the purpose of pre-conditioning outdoor air prior to supplying the conditioned air to a conditioned space, either directly, or, as part of an air-conditioning system. Many energy recover ventilator units available in the market today often employ a pull-push design using two forward-directed blowers. One blower is configured to pull fresh outside air through the unit towards the conditioned space, and the other blower is configured to push stale return air through the unit towards the outside space. Such units can have inherent problems relating to servicing of major system components, preventing moisture build-up, and, the ability to provide free cooling when ambient conditions are appropriate.